This invention relates to textile sliver coiling apparatuses, particularly those equipped with automatic can changer mechanism, and more specifically relates to means for separating the sliver strand extending from the coiler head of such an apparatus to a sliver can which has been filled by the apparatus with sliver.
Numerous types of positively-driven knives, blades, rolls, combs, shears and the like have heretofore been proposed for cutting, severing, rupturing, or otherwise separating a sliver strand associated as aforesaid with a textile coiler. See, e.g., U.S. Pat. Nos. 3,605,198, 3,435,485, 3,381,342, 3,354,513, 3,353,224, 3,246,371, 3,083,416, 2,988,785, Re. 26,807, and British Pat. Nos. 1,172,811 and 929,507. Such positively-driven devices are necessarily complex in nature, and add significantly to the initial cost and the maintenance expense of the coilers with which they are associated.
More simplified sliver-separating techniques are disclosed in U.S. Pat. Nos. 3,249,968 and 3,382,543, and in British Pat. No. 370,081. In accordance therewith, a sliver filled can is moved beneath a member which is intended to securely clamp, against a sliver mass projecting upwardly from the sliver can, a terminal sliver strand extending therefrom. While such procedure is a highly desirable one from the viewpoint of simplicity, certain difficulties are inherent in its attempted utilization. If the force exerted by a clamping member upon the sliver is primarily merely frictional in nature, its magnitude must fall within relatively narrow limits. An excessive frictional force may degrade the sliver and/or disrupt its coiled arrangement within and above the sliver can. On the other hand, if the frictional force is too small, the desired clamping of the sliver strand against the underlying sliver mass will not ensue. Even when a clamping member so balances the foregoing variables as to perform satisfactorily in association with sliver of one given composition, such member frequently will not produce satisfactory results in association with other sliver of different composition. Thus, while the frictional force imposed by a relatively smooth clamping member might satisfactorily restrain a sliver comprised of cotton fiber, it might not do so if the sliver were comprised of snythetic fibers having a longer staple-length, a lesser coefficient of friction and/or a different crimp. Similarly, while the frictional force imposed by a sand-blasted or otherwise roughened surface might restrain and not degrade sliver comprised of synthetic fibers, cotton sliver might adhere thereto or be degraded thereby.